Imaging apparatus with auto-focus function

An imaging apparatus comprising:

• a first image pickup device that converts light from a subject to image data;
• a second image pickup device that coverts light from a subject to image data;
• a first drive section that drives the first image pickup device;
• a second drive section that drives the second image pickup device;
• a first auto-focus section that changes a length of an optical path, of light from the subject that is incident on the second image pickup device, step by step, obtains an auto-focus evaluation value based on image data read from the second image pickup device when the length of the optical path is changed, and controls the length of the optical path of light from the subject that is incident on the second image pickup device to provide a highest auto-focus evaluation value among the obtained auto-focus evaluation values to perform an auto-focus operation on the subject;
• and
• a first control section that controls the first drive section so that the image data is read from the first image pickup device at a predetermined frame rate suitable for displaying a through image, and that controls the first auto-focus section to perform the auto-focus operation while controlling the second drive section so that the image data is read from the second image pickup device at a greater frame rate than the predetermined frame rate.

An auto-focus control method of an imaging apparatus, wherein the imaging apparatus comprises (i) an image pickup device that converts light from a subject to image data, (ii) a drive section that drives the image pickup device, and (iii) an operable shutter button that is capable of being halfway and fully pressed, the method comprising:

• a first determination step comprising determining whether the shutter button is pressed halfway;
• a first focus control step comprising performing an auto-focus operation while controlling the drive section, so that the image data is read from the image pickup device at a predetermined frame rate which is suitable for displaying a through image, when it is determined in the first determination step that the shutter button is pressed halfway;
• a second determination step comprising determining whether the shutter button is fully pressed at once;
• and
• a second focus control step comprising performing an auto-focus operation while controlling the drive section, so that the image data is read from the image pickup device at a greater frame rate than the predetermined frame rate, when it is determined in the second determination step that the shutter button is fully pressed at once.

A computer-readable recording medium storing a program for a computer of an imaging apparatus, wherein the imaging apparatus comprises (i) an image pickup device that converts light from a subject to image data, (ii) a drive section that drives the image pickup device, and (iii) an operable shutter button that is capable of a being halfway pressed and a fully pressed, the program being executable by the computer to control the computer to perform processes comprising:

• a first determination process comprising determining whether the shutter button is pressed halfway;
• a second determination process comprising determining whether the shutter button is fully pressed at once;
• an auto-focus process comprising changing a length of an optical path step by step, obtaining an auto-focus evaluation value based on image data read from the image pickup device for each changed length of the optical path, and controlling the length of the optical path to provide a highest auto-focus evaluation value among the obtained auto-focus evaluation values to perform an auto-focus operation on the subject;
• and
• a process comprising performing the auto-focus process while controlling the drive section so that the image data is read from the image pickup device at a predetermined frame rate suitable for displaying a through image when it is determined in the first determination process that the shutter button is pressed halfway, and performing the auto-focus process while controlling the drive section to drive the image pickup device in a high speed drive so that the image data is read from the image pickup device at a greater frame rate than the predetermined frame rate, when it is determined in the second determination process that the shutter button is fully pressed at once.

A computer-readable recording medium storing a program for a computer of an imaging apparatus, wherein the imaging apparatus comprises (i) a first image pickup device that converts light from a subject to image data, (ii) a second image pickup device that coverts light from a subject to image data, (iii) a first drive section that drives the first image pickup device, and (iv) a second drive section that drives the second image pickup device, the program being executable by the computer to control the computer to perform processes comprising:

• an auto-focus process comprising changing a length of an optical path, of light from the subject that is incident on the second image pickup device, step by step, obtaining an auto-focus evaluation value based on image data read from the second image pickup device when the length of the optical path is changed, and controlling the length of optical path of light from the subject that is incident on the second image pickup device to provide a highest auto-focus evaluation value among the obtained auto-focus evaluation values, to perform an auto-focus operation on the subject;
• and
• a process comprising controlling the first drive section so that the image data is read from the first image pickup device at a predetermined frame rate suitable for through image display, and performing the auto-focus process while controlling the second drive section so that the image data is read from the second image pickup device at a greater frame rate than the predetermined frame rate.